Add grunt bench command

Gruntfile.js

@@ -87,6 +87,17 @@ module.exports = function(grunt) {
       done();
     });
   });
+  grunt.registerTask('bench', function() {
+    var done = this.async();
+
+    var runner = childProcess.fork('./bench/handlebars', [], {stdio: 'inherit'});
+    runner.on('close', function(code) {
+      if (code != 0) {
+        grunt.fatal(code + ' tests failed');
+      }
+      done();
+    });
+  });
 
   grunt.registerTask('build', ['jshint', 'parser', 'dist-dir', 'concat', 'uglify', 'test']);
   grunt.registerTask('default', 'build');

Rakefile

@@ -7,27 +7,6 @@ task :build do |task|
   system "grunt"
 end
 
-directory "vendor"
-
-desc "benchmark against dust.js and mustache.js"
-task :bench => "vendor" do
-  require "open-uri"
-
-  #if File.directory?("vendor/coffee")
-    #system "cd vendor/coffee && git pull"
-  #else
-    #system "git clone git://github.com/jashkenas/coffee-script.git vendor/coffee"
-  #end
-
-  #if File.directory?("vendor/eco")
-    #system "cd vendor/eco && git pull && npm update"
-  #else
-    #system "git clone git://github.com/sstephenson/eco.git vendor/eco && cd vendor/eco && npm update"
-  #end
-
-  system "node bench/handlebars.js"
-end
-
 def dist_files(&block)
   map = {}